Hepatotoxicity: Treatment, causes and applications of medicinal plants as therapeutic agents

Hepatotoxicity, or liver damage, is caused by hepatotoxins, which may source from chemicals, dietary supplements, pharmaceutical drugs, and medicinal plants. Notably, numerous medicinal plants are used to alleviate illness, particularly in traditional systems of medicine, such as Ayurveda and Traditional Chinese Medicine. These systems of medicine have been implemented for centuries for treating various ailments. Some medicinal plants serve as hepatoprotectors against liver damage, while others induce hepatotoxicity. Recent advances in instrumentation and knowledge of active components have allowed research scientists to study the drug metabolic pathways of these phytopharmaceuticals to establish a causal relationship between medicinal plants and their pharmacological effects on the human liver, as a hepatoprotector or a causative agent for hepatotoxicity. The human liver metabolizes substances via oxidation, reduction, hydration, hydrolysis, condensation, conjugation, or isomerization. Interruption of these processes can lead to hepatotoxicity, causing liver cancer, cirrhosis and Hepatitis C, respectively. Such diseases are responsible for higher mortality rates worldwide. The present review focuses on highlighting various plants that are hepatoprotective, hepatotoxic and the challenges faced by phytopharmaceuticals. The article also emphasizes on various agents (bioactives from medicinal plants, industrial toxins and pharmaceutical compounds) that have been reported to cause hepatotoxicity. The article proposes views and beneficial medicinal plants that can help in identification of natural hepatoprotective agents for future natural product based drug discovery.